Testing set for telephone systems



Deco 1 E. JACDBSEN TESTING SET FOR TELEPHONE SY$TEM$ 2 3 a J 4 l wowmfiwgf D/ x v J IITR W n: w LA A n w k 3 4 n. 0 m mm E m .g. 2% a y m 7, 4 I N v m 0/, T T b Ma Mm w Patented Dec. 1, 1925.

UNITED STATES PATENT oFFIcE.

EMIL JACOBSEN, OF NEW YORK, N. Y., ASSIGNOR T0 AMERICAN TELEPHONE AND TELEGRAPH COMPANY, A CORPORATION OF NEW YORK.

TESTING SET FOR TELEPHONE SYSTEMS.

Application filed April 11, 1923. Serial No. 631,418.

1 '0 all whom it may concern Be it known that I, EMIL JAOOBSEN, residing at New York, in the county of New York and State of New York, have invented certain Improvements in Testing Sets for Telephone Systems, of which the following is a specification.

This invention relates to systems for testing electrical conductors and more particularly the conductors of automatic telephone systems.

In automatic telephone systems the subscribers lines may terminate as calling lines at the central oiiice either in automatic line switches or in the banks of automatic line finder switches and these lines also appear as called lines in the banks of connectors. The tip, ring and sleeve terminals of each line of a group are connected by a set. of conductors-t0 the called tip, ring and sleeve terminals, respectively, in the group of connectors having access to this line. In checking this interconnecting wiring prior to cut-over; that is, prior to transferring the subscribers lines from the manual to the automatic central office equipment, it has been the practice to employ the services of two people, one at the connector multiple, the other at the line switches or finders as the case may be, and by some suitable buzzer arrangement to test each conductorfor its continuity and to see that it is properly placed. This method is cumbersome and in addition requires the joint services of at least two testers. Another objection tothis method is that it is at times detrimental to the telephone service, as care is not always exercised in making a test tomake sure that the circuit to be tested is not in use by a subscriber.

The object of this invention is to allow one tester to accomplish the results hitherto requiring the joint services of at least'two testers, and without in any way affecting the service on existing conversational connections.

In accordance with the invention, the

tester is provided with manual means for connecting a testing set to any set of conductors interconnecting the incoming and outgoing set of conductors at the line switches, and

' in the connector banks.

terminals of the subscribers lines, thistest-Q uig set being preferably connected to said at the connectors having access to multiples of the lines under test, the tester being provided with a sender for setting said automatic switching apparatus to pick out the said multiples, whereupon by. applying sig nali'ng currentthereto at the connectors he can determine by means in the test set responsive to this signaling current whether or not the interconnecting wiring is in proper condition.

A feature of this invention is the provision of means for automatically notifying the tester that the lineunder test is busy, to prevent his testing the wiring associated therewith and thus interfering with an existing connection.

Referring to the drawing the invention is illustrated in the cut-over of a telephone system from a manual to an automatic telephone system.

In the drawing a typical subscribers station 1, is shown connected at 6 and 7 to the usual. equipment consisting of a line relay 2, a cut-oil relay 3, jack 4: and lamp.5 required in an existing manual telephone system. At points 160 and 161 the same line is shown connected by means of leads 8 and 9 to the well-known Keith line switch equipment LS, in a full mechanical step-by-step machine switching system, prior to the out- ,over from amanual to a mechanical system.

By .means of the leads 150, 151 and 152 the line is extended to multiples 140, 141, and 142 of a test connector TC, such as is shown for example. in Smith & Campbells Automatic Telephony, first edition at page 355, (Fig. 251). By means of conductors 157, 158, 159 the line is multipled to connector terminals 151, 152 and 153, 154, 155 The test set TS is equipped with two sets of leads, one set, 170, 17.1 and 172 connecting to a subscribers line at the line switch frame LS, while the other set, 15, 4:6, 62 and 64:, is intended for use in conjunction with a test distributor TD, such as is shown, for example, in the publication cited. 7

The test set TS is also equipped with a dial D, a tone transformer T, a receiver 25, a relay 22, and a group of'keys DK, 'IP, RK

and TN, connected in a particular manner to accomplish certain specific results which will be hereinafter more fully explained.

It is believed, that the invention will be fully understood from the following de tailed description of its operation.

The tester connects the clips associated with leads 45, 416, 62 and 64 of the test set TS, to terminals 47 4:8, 63 and 65, respectively, of the test distributor TD, and the clips associated with leads 170, 171 and 172 of the test set TS to terminals 160, 161 and 162, respectively, at the line switch frame LS.

lVith the test set connected in this manner, the following circuit is closed to operate relays and 73, free pole of battery, 73, c5, 64,, e1, e0, 53, 52, e9, 88, 37, 35, so, To, ground. Relays 70 and 73 operate, the latt er establishing a circuit from grounded battery through the winding of slow-release relay 80 front contact and armature 74: of relay 73 to ground, operating, relay 80. The dialing key DK is now operated opening the circuit previously traced at its contacts 36 and 35 and connecting, contacts 30 and 36 to contacts 31 and 3 1, respectively, thus connecting the receiver 25 in series with the circuit previously described through relays 70 and 73. The key DK is so arranged that contacts36 and 84-, and dd-and 31, are closed before. contacts 35. and 36 are opened, thus preventing the momentary release of relays 70 and 7 3 whenever the key DK is operated or released.

hen the dial D is moved oil normal, the off-normal contacts 50 and 51 are closed thus short-circuiting the receiver 25 during the impulsing; period. As the dial returns to normal the impulse springs 52 and 53 are alternately opened and closed, thus alternately opening and closing the circuit through relay 73, which follows the impulses. Relay being slow to release will remain operated as relay 73 periodically releases during the impulsing period. Each time relay 73 releases, a circuit is established from grounded, battery through the vertical magnet side switch wiper contact 88 and brush, 87, front contact 81 and armature 82 of relay 8,0,back Contact 76 and arn'i-ature 7-1 of relay '73: to ground, operating thevertical magnet 85- of the test distributor TD. Each time the vertical magnet 85 operates, theselector rod; (not shown) carrying the brushes 110 to 115,: inclusive, will. be moved upward one step. When the dial returns to normal relay 7 3 remains operated and the circuit through the vertical magnet 85 is held open at; the back contact of relay 7 3. The side switch magnet (not shown) thereupon causes the brushes 87 and 18-1 to advance, the former disconnecting the vertical magnet 85 at contact S8,,and preparing the circuit for the rotary magnet 86st contact 89. dYhen the second digit is dialed relay 73 functions 1 in the manner previously described, and a circuit is established from grounded. battery through the winding of the rotary magnet 86 side switch Wiper contact 89 and brush 87, front contact 81 and armature 82 of relay 80, back contact 7 6 and armature 74 of relay 73 to ground, thus operating the ro tary magnet 86 and causing it to rotate the selector rod carrying the brushes 110 to 115, inclusive, over the contacts in the level selected. lVe will assume that the digits dialed correspond to the level and terminal of the test connector circuit T C and that the brushes 110 to 115, inclusive, of the testdistributor circuit TD are now resting on the contacts 120 to125, inclusive, leading to the test connector circuit TC.

If the test connector circuit TC is busy, relay 100 is operated and a circuit will be established from battery tl'irough the winding of relay 180 of the test distributor circuit TD, side switch contact 183 and brush 181, brush 115, and contact 125, armature 190, and front contact 191 of relay 100 to ground, operating relay 180. Relay 180 when operated connects busy back tone from lead BB, through condenser 18?, front contact 185 and armature 186' of relay 180, leads 188 and 64:, contacts 61 and 60 of the release key R'K, impulse spring contacts and 52 of the dial D, resistance 19, contacts 38 and 37 of the test private key TP', contacts 30 and 31 of the dialing key DK, receiver 25, contacts 34-. and of the dialing hey DK, winding of relay 70 to ground. The ground on multiple 125 will hold the escape magnet of the side switch operated in the well known manner to prevent. the side switch from moving to position The busy back will produce a tone in receiver 25 as an. audible indication that the test connector circuit selected is busy.

If the test connector circuit TC is not busy when the dial returns to normal, the circuit through the rotary magnet 86 will be opened at back contact 76 of relay T3 and the side switch magnet (not shown) will cause brush 8? to advance, disconnecting the rotary magnet 86 at contact; 89.

With the brushes 110 to 11:3, inclusive, of the test d istriljiutor circuit TD resting on the contacts 120 to 125, inclusive, associated. with the test circuit TC, the leads from the test distributor TD are now extended by means of the brushes 110 to 115 and contracts 120; to 125 to the test connector circuit- TC. A circuit will now be establ'isned from grounded battery in the test connector circuit TC, through the right winding of relay 90, contact 124; and brush 11 1, front contact 78 and, armature 77' of. relay T3 in the test distributor circuit TD, brush 113 and contact 128, left winding of relay 90 to ground, operating relay 90. Relay 9O operated, establishes through its front contact 91 and armature a circuit to operate slow to re lease relay 100. \Vhen the third digit is dialed, relay 73 follows the impulses as before and each time relay 73 releases, the circuit through relay 90 is alternately opened and closed at armature 77 and contact 78 of relay 73, causing relay 00 to follow the impulses. Relay 100 being slow to release remains operated throughout the impulsing period. Each time relay 00 releases, a circuit is established from grounded battery through the vertical magnet 105, side switch wiper contact 108 and brush 107, front contact 101 and armature 1.02 of relay 100, back contact 03 and armature 92 of relay 90 to ground, operating the vertical magnet 105 of the test connector circuit TC. Each time the vertical magnet 105 operates the test connector rod (not shown) carrying the brushes 130, 131 and 132 will be moved upward one step. When the dial returns to normal, relays 73 and 90 remain operated, and the circuit through the vertical magnet 105 is held open. The side switch magnet (not shown) of the test connector circuit TC thereupon causes brush 107 to advance to prepare thecircuit for the rotary magnet 106 at contact 109. llhen the final digit is dialed, relays 73 and 90 function in the manner previously described and a circuit is established from grounded battery, through the winding of the rotary magnet 106 of the test connector circuit TC. side switch wiper contact 109 and brush 107, frontcontact 101 and arn'iature 102 of relay 100, back contact 93 and arn'iature 92 of relay 90 to ground thus operating the rotary magnet 106 and causing it to rotate the brushes 130, 131 and over the contacts in the level selected. When the dial returns to normal the circuit through the rotary magnet 106 is held open, and the side switch magnet (not shown) thereuponcauses thcbrush 107 to advance to position 3.

o will assume that the third and fourth digits dialed correspond to the level and terminal of the subscribers line shown in the drawing, therefore the brushes 130, 131 and E12 of the test connector circuit TC are resting on contacts le -0, 141 and 142, respectively. A circuit is now established consisting of two parallel paths, one froi'n grounded battery through the winding'of relay 22, in the test set circuit TS, lead 172 to terminal 162 and the other from grounded battery at the right winding of relay 13 in the line switch circuit LS to terminal 162, where the parallel paths join, lead 1525 contact 142 and brush 132 of the test connector 'ircuit T C, contact 122 and brush 112 of the test distributor circuit TD, armature 71 and contact 72 of relay 7 0 to ground, operating relays and 18. Relay 13 operates and disconnects the subscribers line relay 12 from the circuit. Relay 22 operates and extends load 1.71 through condenser 21 atmature 23, and front contact 24: of relay 22 to contact 83 of the dialing key DK. lVhen the dialing key DK is restored to normal, relays 70 and 73 are again connected directly in series, under control of contacts 36 and 35 of the dialing key DK and a bridge at the line switch frame is established from terminal 160 of the line switch frame LS, lead 170, contacts 32 and 31 of the dialing key DH, receiver 25, contacts S t and 33 of the dialing key DK, front contact 24: and armature 23 of relay 22, condenser 21, lead 171 to terminal. 161 at the line switch frame LS. Thus receiver 25 is connected in bridge with the subscribers line under test to enable the tester to determine by listening in whether or not the line selected is busy before proceeding to test thereon. If the line selected is busy, the tester may either wait until the parties disconnect or transfer 7 the test set TS to some other line in the group and repeat the operation described. Assuming the line 18 not busy the tester operates the tone key TN of the test set TS,

thus establishing a second bridgeacross the subscribefls li ie at the connector group over lead 150, contact 1 and brush 130 of the test connector circuit TC, contact 120 and brush 110 of the test distributor circuit TD, lead 15, winding 44 of the transformer T, condenser 42, contacts 41 and 410 of the tone key TN, lead 16, brush 11.1 and contact 121. of the test distributor circuit TD, brush 1.31 and contact 1 1 1 of the test connector circuit TC, to lead 151 of the subscrihefs line. If leads 150 and 151 are closed betweenterminals 160 and 101 of the line switch frame LS and contacts 140 and 1. 11 of the multiple bank of the test connector circuit TC, the bridge through receiver will he (fODIlOttC-tl to the bridge through winding 14 of the transforn'ier T, thus establishing a complete circuit and the interrupted t'zurrcnt in wind ing -13 of transformer T will be induced in the associated winding 44. thus producing a tone in the receiver 25 of the test set TS as an audible indication that leads 150 and 151 interconnecting the incoming and outgoing switches are properly closed. To check conductor 152, the tester operates the test private key TPas well as the tone key TN thus opening at contacts 37 and of the test private key TP, the circuit originally established through relays 70 and 73 in series. Relay 70 releases. but a new circuit to ground at contacts 38 and of the test private key TP, is established to prevent relay 73 from releasing. When relay releases, ground on its front contact 72 is removed from armature 71, thus opening the parallel circuits through relay 1.3 of the line switch circuits LS, and relay 22 of the test set circuit TS. Relay 22 releases opening the circuit previously described through receiver 25 and winding 44 of the transformer T in series, thus removing the tone from receiver which removal is an indication to the tester that the brush 132 of the test connector circuit TC and relay 22 of: the test set TS are connected to opposite ends of the same conductor and that said conductor is properly connected at either end. lVhen the tester is satisfied that the line is prop erly connected, the release key RK is op era'ted, opening the circuit through relay 73, which releases. ll hen relay T3 releases two circuits are opened, one through relay S0 at trout contact 75, and: the other through relay at trout contact 78, of relay Til. lVhen relay 80 releases a circuit is closed from grounded battery through the release magnet S l ot the test distributor circuit TI), back contact 83 and arn'iature 82 of relay 80, back contact 76 and armature 7st of relay T3 to ground, operating release magnet S-l of the test distributor circuit TD and restoring the test distributor TDto normal. In like manner when relay 9O releases, the circuit through relay of the test connector circuit TC is opened, rcleasi relay 100, and closing the circuitto ope c release magnet 104: of the test connector circuit TC, thus restoring the test connector circuit TC to normal. The test clips associated with loads 170, 171 and 172 of the test set are now removed terminals 160, 1 61 and 162, respectively, of the line under test and connected to a similar group of terminals associated with another line at the same line switch frame and tests are conducted in the same manner as before.

Although the invention has been illustrated as applied to an autoi'naztic telephone system, it is not so limited but is applicable wherever it is desired to test the conti unity of electrical conductors.

What is claimed is:

'l. In a signaling .ystem, a plurality of sets of conductors, a test operators set, means controlled by the test operator for connecting said test set to any set of conductors, automatic switching apparatus asso ciatecl with said test set having access to nurltiples of said conductors, an impulse sender for coi'itrolling said apparatus to connect with said multiples, a source of signaling current, means for connecting the same to the selected conductors, and a device associated with said test set responsim to said signaling current.

2. In a signaling system, a plurality of sets of conductors, a test set, means for connecting saidtest set to any set of coi'idnctors, automatic switching apparatus associated with said test set comprising a phirality ot automatic switches, an impulse sender for controlling one of said switches to select another and the latter to select multiple of said set of conductors, a source of: signaling current, means for connertiiiig the same to the selected set of conductors, a de vice associated vith said test set responsive to said signaling current, a source of busy tone current, and means automatically opcrated by the busy condition of said second switch for connecting said busy tone source to said device.

3. In a signaling system, a plurality of sets oil. conductors comprising a pair ol con ductors and a test conductor, a test operators set including an electro-responsive device, means controlled by the test operator for connecting said test set to any set oi conductors, means for connecting the electro-responsive device included in said test set to any testconductor, autonnitic switching apparatus associated with said test set, an impulse sender for controlling said apparatus to connect with a multiple o'l .aicv desired set (it conductors, a source of signaling current, means for connecting the same to said pair of conductors, a device responsive thereto, and means for remotely controlling at will the electro-responsive device aforesaid to remove said source of signaling current from or connect it to said pair of conductors.

4. In a telephone system, a plurality of subscribers lines, a test operations set includ ing a relay, manual switches controlled by said operator for connecting said test set to any line, a test distributor and a test connector for said test set, a dial for controllil'ig Said test distributor and test connector to connect the latter with the multiples of said line, source of tone current, means For con necting the same to said line through said test distributmr and connector, a device in the test set responsive thereto, and a device for remotely controlling at will the relay in said test to remove said tone current from or connect it to said line.

5. In an automatic telephone exchai'ige system, av central oi'lice, subscribers lines, a group of: automatic switches wherein said lines terminate as calling lines, a group ol automatic switches wherein said lines terminate as called lines, wiring interconnect ing the calling and called terminals of said lines, a test operations set adapted to be connected by the operator to the terminals of a given line at the said first switch group, a test connector adapted to be connected to the terminals of the same line at the said second switch group, means for impressing signaling current on: the wiring of the selected line via said testconnector, and a device associated with said test set responsi e thereto if said wiring is continuous.

6. In an automatic telephone exchange system, a central otlice, subscribers lines, a group of automatic switches wherein said lines terminate as calling lines, a group of automatic switches wherein said lines ter minate as called lines, wiring interconnect ill) ing the calling and called terminals of a given line comprising a pair of conductors interconnecting the talking terminals and a conductor interconnecting the test terninals of said line, a test operators set adapted to be connected by the operator to the lerautomatic switches wherein said lines termi-.

nate as called lines, wiring interconnecting the calling and called terminals of a given line comprising a pair of conductors interconnecting the talking terminals and a conductor interconnecting the test terminals of said line, a test set adapted to be connected to the terminals of a given line at the said first switch group, a test connector adapted to be connected to terminals of the same line at the said second switch group, a source of signaling current, a circuit including said test conductor and a relay adapted to connectsaid source to said pair, a device associated with said test set responsive thereto, and a utianual switch controlling said circuit.

8. In an automatic telephone exchange system, a central office, subscribers lines, a group of automatic switches wherein said lines terminate as calling lines, a group of automatic switches wherein said lines terminate as called lines, wiring interconnecting the calling and called terminals of agiven line comprising a pair of conductors interconnecting the talking terminals and a conductor interconnecting the test terminals of saidline, a test set adapted to be connected to the terminals of a given line at the said first switch group, a test connector adapted to be connected to terminals of the same line at the said second switch group, a tone bridge, a circuit including said test c011- ductor and a relay adapted to connect said tone bridge to said pair, a bridge including a telephone receiver, a manual switch for connecting said bridge to the other end of said pair to respond to said tone current it said pair is continuous.

9. A testing system for testing sets of conductors between the calling and called terminals of a subscribers line comprising a test operators set, means controlled by the operator for connecting said test set to any set of conductors, automatic switching apparatus associated with said test set having access to a multiple of said set of conductors,

an impulse sender for controlling said appaof signaling current, means for connecting the same to the selected set of conductors and a device associated with said test set re sponsiv'e to said signaling current.

10.- 'i' testing system for testing a plurality oi? sets of conductors comprising a test set, means for connecting said test set to any set of conductors, automatic switching apparatus associated with said test set c0mprising a plurality of automatic switches, an impulse sender for controlling one of said switches to select another and the latter to select a multiple of said set of conductors, a source of signaling current, means for connecting the same to the selected set of con doctors, a device associated with said test set responsive to said signaling current, a source of busy tone current, and means automatically operated by the busy condition of said second switch for connecting said busy tone source to said device.

11. A testing system for testing a plurality of sets of conductors, each set consisting ot' a pair of conductors and a testing conductor, comprising a test set including an clectro-responsive device, means for connecting the test set to any set of conductors, means for connecting the electro-responsive device included in the test set to any test conductor, automatic switching apparatus associated with the test set, an impulse sender for controlling the apparatus to connect it to a multiple of the connected set of conductors, a source of signaling current, means for connecting the same to said set of conductors, a device responsive thereto, and means for remotely controlling at will the electro-responsive device aforesaid to remove the source of signaling current from or connect it to said pair of conductors.

12. A testing system for testing a plurality of telephone lines comprising a test operators set including a relay, manual switches controlled by the operator for connecting the test set to any line, a test distributor and a test connector for the test set, a dial for controlling the test distributor and test coir nector to connect the latter with a multiple of said line, a source of tone current, means for connecting the same to said line through the testdistributor and connector, a device in the test set responsive to the tone current, and a device for remotely controlling at will the relay in the test set to remove the tone current from or. connect it to said line.

13. A testing system for testing a plurality of subscribers lines comprising a central ofiice, a group of automatic switches wherein said lines terminate as calling lines, a group of automatic switches wherein said lines terminate as called lines, wiring, interconnecting the calling and called terminals 0t said lines, a test operators set adapted to ratusto connect with said multiple, a source be connected by the operator to the tenni a device associated with said test set respon nals of a given line at said first switch sive thereto if said wiring is continuous. group, a test connector adapted to be con- In testimony whereof, I have signed in 1 nected to the terminals of the same line at name to this specification this 4th day of said second switch group, means for im- April1928.

pressing signaling current. on the wiring of V the selected line via said test connector and EMIL JACOBSEY. 

